Thermal and spectroscopic characterization of several derivatives containing a new organic ring system

Several derivatives containing a new organic ring system, the tropane-6-spiro-5-hydantoin structure (namely 8-alkyl-8-azabicyclo [3.2.1.] octane-6-spiro-5-imidazoline-2,4-diones) have been characterized by thermal (DSC and simultaneous DTA-TG-DTG) and spectroscopic techniques (IR,¹ H-NMR,¹³ C-NMR). X-ray powder diffraction and elemental analysis were applied for structural and molecular characterization. All the compounds melt in the range 160–250°C and undergo decomposition with progressive mass loss after the solid-liquid thermal transition with molecular degradation. It was found that tropane-6-spiro-5-hydantoin derivatives with the hydantoin ring in position are thermally less stable than those containing this ring in position.One of the authors (Dr. M.V.) thanks partial financial support from CICYT through research project PA 86-0317. Thanks are extended to Ms. A. García and Mr. J. C. Rivero for artwork.